Process for improving the properties of ingot-iron and the like.



HANS. GOLDSCHMIDT AND .HANS BIEWEND, OF EssEN-ON-TflE RUfiR, GERMANY ASSIGNORS TO GOLDSCHMIDT THERMIT COMPANY, OF NEW YORK, N. Y., A

conronarronr on NEW YORK.

PROCESS FOR IMPROVING THE PROPERTIES OF INGOT-IRON AND THE LIKE.

ll,l 22,272.

1% Drawing.

T 0 all whom it may concern Be it known that we, HANS GoLnscHMID'r and HANS BIEwEnD, subjects of the King of Prussia, and residents of Essen-on-thelRuhr, in the Province of the Rhine, Germany, have invented certain new and useful Improvements in Processes for Improving the Properties of Ingot-Iron and the like, of which the following is an exact specification.

A process of manufacturing homogeneous metl castings has been previouslyproposed in which heat produced by an aluminothermic reaction was made to act upon certain points of a casting. More particularly this process was intended to be carried out in such a manner, that by introducing an aluminothermic mixture into the solidifying head of an ingot,-the latter was to be kept liquid for a longer time so as to make the ingot capable of receiving further liquid steel. Now practice has shown that although certain parts of the ingot can be heated and kept fluid by this process it is-impossible to remove a great number pf disadvantages by same. So for instance frequently the case may arise that an ingot contains a shrinkage hole or cavity which is not tapering off in a regular manner but shows displacements or interruptions. If now the heat, produced according to the previously known process by an aluminothermic reaction, would be allowed to act upon the head of the ingot,

only the upper part of the cavity interrupted by displacements, but not the lower part of such hole would'be made accessible to the liquid. metal. to be further filled in. Furthermore, many placesof the ingot fre quently show blisters as a consequenceof the inclusion of gases. These hollow spaces cannot at all or can only partly be removed by allowing the heat arising froman aluminothermic reaction to act. at .a certain spot and more particularly at the head of the ingot. n

Now a long series of experiments has shown that by allowing the heat, produced by an aluminothermic reaction to act at certain spots of a casting a thorough improvebe obtained because only a local action by means of fusion or repeated liquefaction is obtained'by this process. Further experiments have shown that the disadvantages above-mentioned can not only be avoided,

Specification of Letters Patent.

Patented Dec. 29, 1914:.

Application filed May 31, 1912. Serial No. 700,785.

but that also a number of important advan tages can be obtained by makin use not of a local thermal effect only, but of a mechanical effect of the aluminothermic mixture.

If namely a certain time after the casting is finished the aluminothermic mixture is introduced into the solidifying ingot, the inthis mechanical motion which is aided by the rapid rise of the light slag all blisters or gas bubbles inclosed or retained in the interior of the ingot are forcedup to the surface. Furthermore, all the segregations which always separate out in the longitudinal axis of an ingot and likewise particles of slag, which accidentally have come into the ingots, are in thesame manner brought to the surface. How perfectly the removal of gas, segregations and the like is effected may be seenfrom the fact that immediately after the reaction the contents of the ingot mold shrink for a considerable amount.

Thenew recognition is that all the factors acting unfavorably upon .the properties of the ingot are eliminated by producing a whirlinmotion directed from the bottom to the sur ace within the solidifying ingot the interior of which is still fluid. This whirling motion is preferably caused by introducposed of one or more metal oxids and 'aluminum or other reducingmetals, by the re action of which heat is produced. l The bubbling and whirling motion which is the cause of improvingthe qualities of the cast inget can not only beprodu'ced by the introduction of an aluminothermic mixture. but also by various other means for instance with theiaidof explosives the speed of explosion of which is particularly small,

or by means of gases introduced under high pressure, which do not dissolve within the ingot metal, or finally by producing electric currents within the liquid metal. Now, in order to obtain the result that the whirling motion and its efi'ects extend throughout the ingot, it has proved necessary that for instance the box or the like containing the aluminothermic mixture, is pushed down as far as possible to the bottom of themold.

- laid upon the molds which then remain on their places till the ingots are perfectly solidified.

The advantages above described are apparent for instance if low carbon steel without silicon in form of ingots is rolled to sheet metal. The practice has shown that the waste of the sheet rolled from material treated according to the above process is limited to about 0.3%, whereas the waste in the manufacturing of sheet made ofordinary ingots is much higher, in some cases even fifty times and more. Moreover with the" process described, besides the advantages above-mentioned some other advantages are obtained which consist in'an essential refining action on the material. It is however not possible to. give numerical. values for them in the same manner as above.

What we claim is: a f

1. A process for improving the properties of metals .cast in ingots which consists in producing in the fluid interior of the metal body shortly before solidification a whirling or bubbling motion directed from the bottom to the surface.

2. A process for improving the properties of metals cast in ingots which consists in producing in the fluid interior of the metal body shortly before solidification a whirling or bubbling motion directed from the bottom' to the surface and extending throughout the ingot body.

3. A process for improving the properties of iron, steel and the like cast in ingots which'consists in producing in the fluid interior of the iron and the like material a whirling or bubbling motion directed from the bottom to the surface and extending throughout the ingot body.

4. A process for improving the properties of iron, steel and the like cast in ingots which consists in introducing an aluminothermic mixture into the fluid metal of the ingot thereby producing a whirling or bubbling motion in the interior of the ingot mass, and extending throughout the ingot bo 5. A process for improving the properties of iron, steel and the like cast in ingots which consists in introducing an aluminothermic mixture into the fluid metal down to the bottom of the latter, thereby produc: ing a whirling or bubbling motion in the interior of the mass directed from the bottom to the surface.

HANS GOLDSCHMIDT. [L.S.] HANS BIEVEND. [L.S.]

l/Vitnesses as to Hans Goldschmidt:

Jnssrn E. Pos'r, WM. C. Cum'rs.

Vvitnesses as to Hans Biewend:

HELEN Norms,

ALBERT NUFER. 

